Utility test lamp



July 28, 1936. cL H. RIBBLE Er AL' UTILITY TEST LAMP.

- Filed Sept. 14, 1935 Vl BM WITNESSES Patented July 28, 1936 UNETED STATES PATENT OFFICE UTILITY TE ST LAMP Application September 14, i935, Serial No. 40,634

1 Claim.

unit designed to offer maximum safety and so cushioned as to protect its lamp bulbs and filaments even though the unit is accidentally dropped.

A further object is to provide a unit of this character having a removable plate containing the lamp sockets, which is designed to permit easy wiring as well as socket replacements at any time with a minimum of delay.

A further object is to provide a unit of this character having a casing of oil-resistant exible rubber and which is of small'and compact size and shock-proof both electrically and mechanically. Our improved unit embodies many features of novelty and advantage, all of which will be more fully hereinafter described and pointed out in the claim.

In the accompanying drawing- Fig. l is a view in longitudinal section through the casing of our improved unit.

Fig. 2 is a View in transverse section on the line 2--2 of Fig. 1.

Fig. 3 is a view in longitudinal section of a modified form of casing.V

I represents a casing which is composed of oilresistant flexible rubber or other suitable material which is preferably of general oblong shape in cross section and is formed with a closed end 2, the opposite end of the casing being open. In the casing i a removable lamp-supporting plate 3 is located, and to insure the proper positioning of said plate in the casing the latter is formed with an internal shoulder il limiting the inward movement of the plate and spaced from the shoulder 4, the casing is formed with an internal rib 5 and as the casing is of flexible material the plate can be forced past the rib down upon the shoulder when the rib will spring inwardly and conne the plate and securely hold itin proper position. This plate 3 supports lamp sockets 6 in which suitable electric light bulbs 7 are removably held. The opposite sides of the casing I are provided with openings 8 through which the lamps may be observed, and it is of course to be denitely understood that the invention is not limited to any particular number or shape of such openings.

The closed end 2 of the casing has a tubular integral extension 9 constituting a handle, and through the bore I of this tubular extension the cable II enclosing electric wires I2 is projected. The wires I2 preferably extend through perforations in a fiber strain washer I3 located against the inner face of the end 2 and are connected to (Cl. 2MB-11.2)

binding posts I4 on the lamp sockets 6. To prevent strain on the coupled engagement of the wires with the binding posts the wires are preferably knotted as shown at I above the plate I3, as clearly shown in Fig. 1 of the drawing. The tubular extension or handle 9 is provided with internal annular ribs or flanges I'I and I3 respectively, at its ends. These flanges or ribs result in reducing the diameter of the bore so that the diameter at the ribbed portion 1s normally less than the diameter of the cable II, so that when the cable is forced through the bore I0 these restricted portions will bind or engage the cable and wires and render the tubular handle dustproof, that is to say, such a construction will prevent the entrance of dust, dirt, or water which might otherwise work through the handle into the interior of the casing.

In the modification illustrated in Fig. 3 of the drawing, the casing is formed of two sections I9 and removably coupled. A simple form of coupling is to provide the section I9 with an external groove 2| and form a bead 22 on the end of section 2D which will spring into this groove 2| and hold the parts together. However, by sufficient force the sections may be separated so that the lamps may be completely exposed for purposes of complete illumination and also to give access to the lamps and their sockets.

While we have illustrated and described what we believe to be the preferred embodiments of the invention, it is obvious that various changes might be made in the general form and arrangement of parts without departing from the invention, hence we do not wish to be limited to the precise details set forth but consider ourselves at liberty to make such changes and alterations as fairly fall within the spirit and scope of the appended claim.

We claim:

A utility test lamp, comprising a casing of exible material of general oblong shape in cross section, said casing having an open end and a closed end and having parallel side walls and narrower end walls connecting the side walls, said side walls having aligned openings therein, a removable lamp-supporting plate resiliently held in the casing, lamps supported by the plate and in line with the openings in the walls of the casing, a tubular handle at the closed end of the casing, a cable extending through the tubular handle, wires in the cable, a perforated strain washer in the casing through which the wires are projected and knotted, and internal annular beads 0r flanges at the respective ends of the bore or handle gripping the cable and wires.

CHAUNCEY H. RIBBLE. ALEXANDER J. HEIDT. 

